In previous studies we have described various aspects of the dispersion, chromatographic behavior, and kinetics of various adenylate cyclases as well as various properties of membranes and of the assay of adenylate cyclase that can lead to artifacts in measured activity. The methodology involved in adenylate cyclase studies has been improved by the development of an enzymatic procedure for the preparation of (alpha 32P)ATP. We have also been investigating the mechanisms of the stimulatory and inhibitory actions of adenosine in platelets and have extended this recently to the striatum. Our immediate objectives in the proposed studies are to complete our current studies on the control of the striatal adenylate cyclase by adenosine and dopamine. These studies will provide the basis on which we can then: a) develop techniques for measuring (3H)adenosine (or(3H)adenosine analogs) binding to proteins that are involved, respectively, with the stimulatory and inhibitory effects of adenosine, and b) develop affinity chromatography systems, with adenosine analogs, coupled to agarose variously through the ribose and N6-positions, that can be used for the purification of adenosine-dependent modulator protein(s) that would be specifically associated with the inhibitory or stimulatory actions of adenosine.